I am wondering if this is possible. Could I use one connection for downstream while using another for upstream?

My setup would be as follows

Upstream Connection ----VPN----->|
| |
MT ------- "Central Server" -----> The Internet
| |
Downstream Connection ---VPN---->|


The central server would be a linux VPS. There would be VPN tunnels from both connections over the internet to the central server. The central server would then NAT the connections behind its public IP. The central server has a symmetrical 50mb connection.

any feedback would be great.


EDIT: My diagram didn't come out right. If anyone needs clarification let me know.

Thanks